1. Field of the Invention
The present invention relates to finely-divided polymeric solids having particle sizes from about 0.1 to 10 microns dispersed in a polyol. More particularly, the invention relates to finely-divided solid polymers prepared by polymerizing in the presence of a free-radical initiator and an organic solvent, an ethylenically unsaturated monomer or mixture of monomers, in the presence of an effective amount of a preformed polymeric stabilizer. The solid polymers, when dispersed in a polyol, are useful in the preparation of polyurethane foams.
2. Description of the Prior Art
The prior art, as evidenced by U.S. Pat. Nos. 3,652,659; 3,875,258; 3,950,317; 3,931,092; and Reissue Patent Nos. 28,715 and 29,014 teach the preparation of graft polymer dispersions which are useful in the preparation of polyurethanes by the polymerization of ethylenically-unsaturated monomers. These patents disclose various methods of preparing graft polymer dispersions generally in the presence of polyols. German Patent Application No. 2,756,601 discloses the use of a stabilizer which consists of a polymer of an ethylenically unsaturated monomer or mixture of such monomers which is chemically bound to a propylene oxide polymer having a number average molecular weight of at least about 800 and having a viscosity of more than about 40,000 cps at 25.degree. C. Applicants are unaware of any prior art which relates to the finely-divided solid polymers of the type described herein prepared by polymerization in the presence of the claimed preformed polymeric stabilizer consisting of an alkoxylated styrene-allyl alcohol polymer.